Electrosurgical forceps

ABSTRACT

An electrosurgical forceps includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. The jaw members are configured to facilitate tissue treatment, tissue division, and blunt tissue dissection.

BACKGROUND

The present disclosure relates to electrosurgical instruments and, more particularly, to an electrosurgical forceps that facilitates tissue treatment, tissue division, and blunt tissue dissection.

A surgical forceps is a plier-like instrument which relies on mechanical action between its jaws to grasp tissue. Electrosurgical forceps utilize both mechanical clamping action and electrical energy to treat tissue, e.g., coagulate, cauterize, and/or seal tissue.

Typically, once tissue is treated, the surgeon has to accurately sever the treated tissue. Accordingly, many electrosurgical forceps have been designed which incorporate a knife configured to effectively divide tissue after treating tissue. Of course, the knife may also be utilized to divided tissue without or prior to tissue treatment.

Electrosurgical forceps are also often utilized for blunt tissue dissection such as, for example, in order to provide access to underlying tissue(s) to be treated and/or divided.

A design challenge is thus presented with respect to the design of an electrosurgical forceps and, more specifically, with respect to striking a balance between the benefits that certain features may provide to facilitate some aspects (tissue treatment, tissue division, and/or blunt tissue dissection, for example), versus the challenges that such features may provide to other aspects (tissue treatment, tissue division, and/or blunt tissue dissection, for example).

SUMMARY

As used herein, the term “distal” refers to the portion that is being described which is further from a surgeon, while the term “proximal” refers to the portion that is being described which is closer to a surgeon. Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein.

An electrosurgical forceps provided in accordance with aspects of the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members includes a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. A ratio of a width of the distal tip portion of each of the first and second jaw members to a length of the distal tip portion of each of the first and second jaw members is in a range of from about 1.45 to about 1.70.

In an aspect of the present disclosure, the ratio is in a range of from about 1.50 to about 1.65; in another aspect, the ratio is in a range of from about 1.55 to about 1.60; in still another aspect, the ratio is about 1.57.

In an aspect of the present disclosure, the distal tip portion of each of the first and second jaw members defines a half-ellipse, and the curved distal perimeter defines a half-circumference of the half-ellipse.

In another aspect of the present disclosure, the width is a minor diameter of the half-ellipse and/or the length is a major radius of the half-ellipse.

In yet another aspect of the present disclosure, each of the first and second jaw members is curved along a portion of a length thereof.

In still another aspect of the present disclosure, a lockbox configuration surrounds the pivot.

Another electrosurgical forceps provided in accordance with aspects of the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members includes a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. A ratio of a height defined between the outwardly-facing sides of the first and second jaw members at the distal tip portions thereof in the closed position to a length of the distal tip portion of each of the first and second jaw members is in a range of from about 2.25 to about 2.55.

In an aspect of the present disclosure, the ratio is in a range of from about 2.30 to about 2.50; in another aspect, the ratio is in a range of from about 2.35 to about 2.45; in still another aspect, the ratio is about 2.40.

In another aspect of the present disclosure, the distal tip portion of each of the first and second jaw members defines a half-ellipse, the curved distal perimeter defines a half-circumference of the half-ellipse, and the length is a radius of the half-ellipse.

In yet another aspect of the present disclosure, the height is measured at a diameter of the half-ellipse of the distal tip portion of each of the first and second jaw members.

In still another aspect of the present disclosure, each of the first and second jaw members is curved along a portion of a length thereof.

In still yet another aspect of the present disclosure, in the closed position, the distal tip portions of the first and second jaw members define a gap distance therebetween of equal to or less than about 0.025 inches.

Still another electrosurgical forceps provided in accordance with aspects of the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members defines a longitudinal axis and a curved distal section curving off of the longitudinal axis. The curved distal section of each of the first and second jaw members defines a length and includes a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. A ratio of the length of the curved distal section of each of the first and second jaw members to a distance the distal tip portion of each of the first and second jaw members is displaced from the respective longitudinal axis of that jaw member is in a range of from about 2.40 to about 2.80.

In an aspect of the present disclosure, the ratio is in a range of from about 2.50 to about 2.70; in another aspect, the ratio is in a range of from about 2.55 to about 2.65; in still another aspect, the ratio is about 2.60.

In another aspect of the present disclosure, the distal tip portion of each of the first and second jaw members defines a half-ellipse, the curved distal perimeter of each of the first and second jaw members defines a half-circumference of the half-ellipse, and the length and the distance are measured to a point where a symmetrically bisecting radius of the half-ellipse meets the curved distal perimeter.

In still another aspect of the present disclosure, each of the first and second jaw members further includes a straight proximal section centered on the longitudinal axis thereof, the curved distal section extending from the straight proximal section. In aspects, the straight proximal section defines a length of up to about 0.125 inches.

In yet another aspect, the curved distal section of each of the first and second jaw members defines an angle of curvature of about 15 degrees to about 25 degrees; in aspects, about 17 degrees to about 23 degrees; and, in other aspects, about 19 degrees to about 21 degrees.

Another electrosurgical forceps provided in accordance with the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members defines a longitudinal axis and a curved distal section curving off of the longitudinal axis. The curved distal section of each of the first and second jaw members defines a width at the proximal end thereof. The curved distal section of each of the first and second jaw members includes a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. The distal tip portion of each of the first and second jaw members defines a diameter transversely thereacross. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. A ratio of the width of the proximal end of the curved distal section of each of the first and second jaw members to the width of the diameter of the distal tip portion of each of the first and second jaw members is in a range of from about 1.60 to about 2.00.

In an aspect of the present disclosure, the ratio is in a range of from about 1.70 to about 1.90; in another aspect, the ratio is in a range of from about 1.75 to about 1.85; in yet another aspect, the ratio is about 1.80.

In another aspect of the present disclosure, the distal tip portion of each of the first and second jaw members defines a half-ellipse, the curved distal perimeter of each of the first and second jaw members defines a half-circumference of the half-ellipse, and the diameter of each of the first and second jaw members is a full diameter of the half-ellipse.

In still another aspect of the present disclosure, each of the first and second jaw members further includes a straight proximal section centered on the longitudinal axis thereof, the curved distal section extending from the straight proximal section. In aspects, the straight proximal section defines a length of up to about 0.125 inches.

In another aspect of the present disclosure, the straight proximal section defines a substantially constant width equal to the width of the proximal end of the curved distal section.

In yet another aspect, the curved distal section of each of the first and second jaw members defines an angle of curvature of about 15 degrees to about 25 degrees; in aspects, about 17 degrees to about 23 degrees; and, in other aspects, about 19 degrees to about 21 degrees.

Still yet another electrosurgical forceps provided in accordance with aspects of the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members includes an opposed, inwardly-facing side having a proximal end and a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. A pivot couples the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. A ratio of a height of the first and second jaw members at the proximal ends of the inwardly-facing sides of the first and second jaw members to a height of the first and second jaw members at the distal tip portions of the first and second jaw members is in a range of about 1.80 to about 2.10.

In an aspect of the present disclosure, the ratio is in a range of from about 1.85 to about 2.05; in another aspect of the present disclosure, the ratio is in a range of from about 1.90 to about 2.00; in still another aspect of the present disclosure, the ratio is about 1.94.

In another aspect of the present disclosure, the distal tip portion of each of the first and second jaw members defines a half-ellipse with the curved distal perimeter of each of the first and second jaw members defining a half-circumference of the half-ellipse. In such aspects, the height of the first and second jaw members at the distal tip portions thereof is measured at a full diameter of the half-ellipse of each of the first and second jaw members.

In still another aspect of the present disclosure, a lockbox configuration surrounds the pivot and the proximal end of the inwardly-facing side of each of the first and second jaw members is defined at the point where at least one of the first or second jaw members extends distally from the lockbox configuration.

In yet another aspect of the present disclosure, each of the first and second jaw members is curved along a portion of a length thereof.

Another electrosurgical forceps provided in accordance with aspects of the present disclosure includes first and second shaft members and first and second jaw members extending distally from the respective first and second shaft members. Each of the first and second jaw members includes a distal tip portion defined as an area within a concave side of a curved distal perimeter of the distal tip portion. A pivot coupling the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position. Each of the first and second jaw members defines a stiffness as measured between at least one of: a center of the pivot and a point within the area of the respective jaw member or a proximal end of the respective jaw member to a point within the area of the respective jaw member, of from about 80 lb/in to about 300 lb/in.

In aspects, the stiffness of the first jaw member is from about 80 lb/in to about 180 lb/in and/or the stiffness of the second jaw member is from about 110 lb/in to about 225 lb/in. The stiffnesses of the jaw members may be similar (in embodiments, about the same) or may be different.

In another aspect of the present disclosure, each of the first and second jaw members includes an opposed, inwardly-facing surface. In such aspects, the stiffness of each of the first and second jaw members is measured in a direction normal to the respective opposed, inwardly-facing surface thereof.

In yet another aspect of the present disclosure, each of the first and second jaw members is curved along a portion of a length thereof.

In still another aspect of the present disclosure, the stiffness of each of the first and second jaw members is measured in a direction normal to a direction of curvature of the first and second jaw members.

In still yet another aspect of the present disclosure, a lockbox configuration surrounds the pivot and the proximal end of the inwardly-facing side of each of the first and second jaw members is defined at the point where at least one of the first or second jaw members extends distally from the lockbox configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects and features of the present disclosure are described hereinbelow with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views:

FIG. 1 is a side, perspective view of an electrosurgical forceps provided in accordance with aspects of the present disclosure;

FIG. 2A is a perspective view from one side of the forceps of FIG. 1 with portions of outer housings of first and second shaft members removed to illustrate the internal components therein;

FIG. 2B is a perspective view from the other side of the forceps of FIG. 1 with other portions of the outer housings of the shaft members removed to illustrate the internal components therein;

FIG. 3A is a perspective view of an inner frame and a jaw member of the first shaft member of the forceps of FIG. 1;

FIG. 3B is an enlarged, side, perspective view of a distal portion of the jaw member of FIG. 3A;

FIG. 3C is perspective view of another body plate of the inner frame and jaw member configured for use with the forceps of FIG. 1;

FIG. 4A is a perspective view of an inner frame and a jaw member of the second shaft member of the forceps of FIG. 1;

FIG. 4B is an enlarged, perspective view of a distal portion of the jaw member of FIG. 4A;

FIG. 5A is a perspective view of a distal portion of the forceps of FIG. 1 illustrating the first and second jaw members pivotably coupled to form the end effector assembly;

FIG. 5B is a transverse, cross-sectional view taken along section line “5B-5B” in FIG. 5A;

FIG. 5C is a first perspective view of a pivot member of the end effector assembly of the forceps of FIG. 1

FIG. 5D is a second perspective view of the pivot member of the end effector assembly of the forceps of FIG. 1;

FIG. 6 is a side, perspective view of the forceps of FIG. 1 with portions removed to illustrate a knife deployment mechanism of the forceps;

FIG. 7 is a rear view of a pair of triggers and a first linkage of the knife deployment mechanism of FIG. 6;

FIG. 8 is a side view of a handle of the first shaft member of the forceps of FIG. 1 shown operably coupled to a first linkage of the knife deployment mechanism of FIG. 6;

FIG. 9 is a side view of a knife of the forceps of FIG. 1;

FIG. 10 is a perspective view of a distal portion of the knife of FIG. 9;

FIG. 11A is an enlarged, side view of a connector end of one of the pair of triggers configured for use with the knife deployment mechanism of FIG. 6;

FIG. 11B is an enlarged, side view of a portion of the outer housing of the first shaft member of the forceps of FIG. 1 including a keyed aperture configured to receive the connector end of the trigger of FIG. 11A;

FIGS. 12A and 12B are enlarged, internal views illustrating rotation of the connector end of the trigger of FIG. 11A within the keyed aperture of the outer housing of the first shaft member of FIG. 11B;

FIG. 13 is a transverse, cross-sectional view illustrating the pair of triggers of FIG. 11A engaged with the outer housing of the first shaft member of FIG. 11B and the knife deployment mechanism of FIG. 6;

FIG. 14 is a side view of a proximal portion of the forceps of FIG. 1 with portions removed to illustrate a knife lockout of the forceps;

FIG. 15 is a rear view of the forceps of FIG. 1;

FIG. 16A is a top, perspective view of a switch assembly of the forceps of FIG. 1;

FIG. 16B is a bottom, perspective view of the switch assembly of FIG. 16A;

FIGS. 17A-17H illustrate assembly of the forceps of FIG. 1 in accordance with the present disclosure;

FIG. 18 is a longitudinal, cross-sectional view of a portion of the forceps of FIG. 1 with components removed to illustrate another knife deployment mechanism provided in accordance with the present disclosure;

FIG. 19 is a longitudinal, cross-sectional view of a portion of the forceps of FIG. 1 with components removed to illustrate yet another knife deployment mechanism provided in accordance with the present disclosure;

FIGS. 20A and 20B are respective outer and inner side views of a distal portion of another knife configured for use with the forceps of FIG. 1;

FIGS. 21A and 21B are respective outer and inner side views of a distal portion of still another knife configured for use with the forceps of FIG. 1;

FIGS. 22A and 22B are respective outer and inner side views of a distal portion of yet another knife configured for use with the forceps of FIG. 1;

FIGS. 23A and 23B are respective outer and inner side views of a distal portion of still yet another knife configured for use with the forceps of FIG. 1;

FIGS. 24A and 24B are respective outer and inner side views of a distal portion of another knife configured for use with the forceps of FIG. 1;

FIGS. 25A and 25B are respective outer and inner side views of a distal portion of yet another knife configured for use with the forceps of FIG. 1;

FIG. 26A is an outer side view of a distal portion of another knife configured for use with the forceps of FIG. 1;

FIG. 26B is an enlarged view of the area of detail indicated as “26B” in FIG. 26A;

FIG. 27A is an outer side view of a distal portion of still another knife configured for use with the forceps of FIG. 1;

FIG. 27B is an enlarged, perspective view of a distal end portion of knife of FIG. 27A; and

FIG. 28 is an enlarged, bottom view of a distal portion of one of the jaw members of the forceps of FIG. 1;

FIG. 29 is an enlarged, bottom view of one of the jaw members of the forceps of FIG. 1;

FIG. 30 is an enlarged, side view of a distal portion of the forceps of FIG. 1; and

FIG. 31 is a top view of the tissue-contacting plate of one of the jaw members of the forceps of FIG. 1.

DETAILED DESCRIPTION

Referring generally to FIGS. 1-2B, a forceps 100 provided in accordance with the present disclosure includes first and second shaft members 110, 120 each having a proximal end portion 112 a, 122 a and a distal end portion 112 b, 122 b. An end effector assembly 200 of forceps 100 includes first and second jaw members 210, 220 extending from distal end portions 112 b, 122 b of shaft members 110, 120, respectively. Forceps 100 further includes a pivot member 130 pivotably coupling first and second shaft members 110, 120 with one another, a knife 140 (FIGS. 9-10), a knife deployment mechanism 150 for selectively deploying knife 140 (FIGS. 9-10) relative to end effector assembly 200, a knife lockout 170 for inhibiting deployment of knife 140 (FIGS. 9-10) prior to sufficient closure of jaw members 210, 220, and a switch assembly 180 for enabling the selective supply of electrosurgical energy to end effector assembly 100. An electrosurgical cable 300 electrically couples forceps 100 to a source of energy (not shown), e.g., an electrosurgical generator, to enable the supply of electrosurgical energy to jaw members 210, 220 of end effector assembly 200 upon activation of switch assembly 180.

Continuing with reference to FIGS. 1-2B, each shaft member 110, 120 includes an inner frame 114, 124, an outer housing 116, 126 surrounding at least a portion of the respective inner frame 114, 124, and a handle 118, 128 engaged with the respective outer housing 116, 126 towards proximal end portions 112 a, 122 a of shaft members 110, 120, respectively. Inner frames 114, 124 are described in greater detail below. Outer housings 116, 126 enclose and/or operably support the internal components disposed within shaft members 110, 120. More specifically, as detailed below, outer housing 116 of shaft member 110 encloses and supports at least a portion of inner frame 114, knife deployment mechanism 150, and lockout 170, while outer housing 126 of shaft member 120 receives electrosurgical cable 300 and encloses and supports at least a portion of inner frame 124, switch assembly 180, and the lead wires 310 of electrosurgical cable 300. Handles 118, 128 are engaged with outer housings 116, 126 towards proximal end portions 112 a, 112 b of shaft members 110, 120 and extend outwardly from shaft members 110, 120. Handles 118, 128 define finger holes 119, 129 configured to facilitate grasping and manipulating shaft members 110, 120.

Referring to FIG. 3A, inner frame 114 of shaft member 110 includes a body plate 115 a and a reinforcing plate 115 b attached to body plate 115 a, e.g., via welding, to provide increased lateral stiffness and structural support thereto. In embodiments, reinforcing plate 115 b may be welded to body plate 115 a in at least two places, e.g., towards the proximal and distal end portions thereof. The increased lateral stiffness provided by reinforcing plate 115 b helps ensure alignment of depressible button 183 b (FIG. 16A) of switch assembly 180 with outer housing 116 of shaft member 110 (FIG. such that depressible button 183 b is depressed and switch assembly 180 activated upon sufficient approximation of shaft members 110, 120 (see also FIG. 15).

Inner frame 114 defines one or more location apertures 115 c, a trigger aperture 115 d, and a longitudinal slot 115 e that each extend through both body plate 115 a and reinforcing plate 115 b. The one or more location apertures 115 c are configured to receive corresponding posts 117 of outer housing 116 to locate and maintain inner frame 114 in position within outer housing 116. Body plate 115 a extends distally beyond reinforcing plate 115 b to enable attachment of jaw support 212 of jaw member 210 thereto, e.g., via staking or other suitable engagement. The portion of body plate 115 a that extends distally beyond reinforcing plate 115 b further defines a pivot aperture 115 f extending transversely therethrough. A stop protrusion 115 g extends from inner frame 114 into pivot aperture 115 f, as detailed below. Body plate 115 a of inner frame 114 further defines a longitudinal channel 115 h oriented towards reinforcing plate 115 b such that reinforcing plate 115 b encloses a portion of longitudinal channel 115 h.

With additional reference to FIG. 3B, as noted above, jaw support 212 of jaw member 210 is staked or otherwise engaged, e.g., welded, press-fit, mechanically locked, etc., to the portion of body plate 115 a that extends distally beyond reinforcing plate 115 b. Jaw member 210 further includes an electrically-conductive, tissue-contacting plate 214 and an insulative housing 216. Tissue-contacting plate 214 defines a longitudinally-extending knife channel 215 a extending at least partially therethrough and may include one or more stop members 215 b disposed thereon and electrically isolated therefrom. Insulative housing 216 of jaw member 210 is overmolded or otherwise secured about a portion of jaw support 212, tissue-contacting plate 214, and body plate 115 a of inner frame 114 of shaft member 110. Insulative housing 216 includes a distal portion 217 a and a proximal extension portion 217 b. Proximal extension portion 217 b of insulative housing 216 is configured to extend proximally along body plate 115 a of inner frame 114 to (or proximally beyond) pivot aperture 115 f thereof. The electrical lead 310 (FIGS. 2A and 3B) configured to electrically couple to tissue-contacting plate 214 is captured between body plate 115 a and proximal extension portion 217 b of insulative housing 216 to protect and facilitate routing of the electrical lead 310 (FIGS. 2A and 3B) from shaft member 120, around pivot aperture 115 f, and distally therefrom to electrically couple to tissue-contacting plate 214.

Distal portion 217 a of insulative housing 216 of jaw member 210 extends about the periphery of tissue-contacting plate 214 and defines a main section 218 a, a raised section 218 b, and a beak section 218 c. Main section 218 a of distal portion 217 a of insulative housing 216 extends on either side of tissue-contacting plate 214 and is offset relative thereto such that tissue-contacting plate 214 is raised relative to main section 218 a. Raised section 218 b of distal portion 217 a of insulative housing 216 extends distally from main section 218 a on either side of tissue-contacting plate 214 and is still recessed relative to tissue-contacting plate 214 but is closer to being co-planar with tissue-contacting plate 214 as compared to main section 218 a. Beak section 218 c of distal portion 217 a of insulative housing 216 is disposed distally of tissue-contacting plate 214 and extends to or beyond tissue-contacting plate 214. Beak section 218 c inhibits tissue from entering the area between jaw members 210, 220 of end effector assembly 200 when end effector assembly 200 is disposed in the closed position and utilized for blunt dissection (see FIG. 5A).

Referring to FIG. 3C, another embodiment is provided wherein body plate 115 a′ of inner frame 114′ does not define the pivot aperture therethrough but, rather, terminates proximally of the pivot location. In this embodiment, jaw support 212′ of jaw member 210′ defines pivot aperture 115 f′ and extends from the distal body portion of jaw member 210′ proximally beyond the pivot location to enable jaw support 212′ to be staked or otherwise engaged to body plate 115 a′ of inner frame 114′ proximally of the pivot location. Pivot aperture 115 f′ defined within jaw support 212′ receives pivot member 130 similarly as detailed above with regard to pivot aperture 115 f (se FIGS. 3A and 5C). In this embodiment, jaw support 212′ may include, in the areas where jaw support 212′ replaces body plate 115 a (FIG. 3A), any of the features of body plate 115 a of inner frame 114 (see FIG. 3A) and may likewise include any of the features of jaw support 212 (FIG. 3A).

Continuing with reference to FIG. 3C, in embodiments, the jaw support, e.g., jaw support 212′, may further define a notch 115 i′ configured to receive an edge 125 g (FIG. 17B) of distal clevis portion 125 c of inner frame 124 of shaft member 120 (FIG. 4A) therein to define the spaced-apart position of shaft members 110, 120 (see FIGS. 2A-2B). That is, receipt of edge 125 g (FIG. 17B) within notch 115 i′ inhibits further movement of shaft members 110, 120 apart from one another, thus defining the furthest spaced-apart portion of shaft member 110, 120 (see FIGS. 2A-2B).

Turning to FIG. 4A, inner frame 124 of shaft member 120 includes an elongated body portion 125 a, an enlarged proximal portion 125 b, and a distal clevis portion 125 c. Enlarged proximal portion 125 b of inner frame 124 provides additional structural support to shaft member 120 and defines one or more location apertures 125 d that, similarly as with location apertures 115 c of inner frame 114 of shaft member 110 (FIG. 3A), are configured to receive corresponding posts 127 of outer housing 126 to locate and maintain inner frame 124 in position within outer housing 126. Elongated body portion 125 a of inner frame 124 extends through outer housing 126 of shaft member 120, while distal clevis portion 125 c of shaft member 120 extends distally from outer housing 126. Distal clevis portion 125 c may be welded to, monolithically formed with, or otherwise engaged to elongated body portion 125 a of inner frame 124. Distal clevis portion 125 c of inner frame 124 is detailed below.

Elongated body portion 125 a defines a flexibility, e.g., is flexible an amount according to a spring constant thereof, thus enabling flexure of elongated body portion 125 a in response to application of a jaw force at jaw member 220. This configuration enables the application of a jaw force within a particular range, e.g., between about 3 kg/cm² and about 16 kg/cm², when shaft members 110, 120 are disposed in the approximated position corresponding to the closed position of jaw members 210, 220. Referring also to FIGS. 3A, 3B, and 4B, in embodiments, in addition to the flexion of elongated body portion 125 a providing a jaw force within a particular range, flexion of the jaw members 210, 220 may also contribute to providing a jaw force within a particular range. More specifically, due to the relatively fine configuration of the jaw members 210, 220 and the fact that the jaw members 210, 220 taper in height and width from the proximal ends to the distal ends thereof, the jaw members 210, 220 themselves provide flexibility that, in conjunction with the flexibility of elongated body portion 125 a, provide a jaw force within a particular range to facilitate tissue treatment.

Referring to FIGS. 4A and 4B, jaw member 220 of end effector assembly 200 is supported on a distal extension (not shown) of distal clevis portion 125 c of inner frame 124 of shaft member 120. The distal extension (not shown) of distal clevis portion 125 c of inner frame 124 serves as the jaw frame of jaw member 220. Jaw member 220 further includes an electrically-conductive, tissue-contacting plate 224 and an insulative housing 226. Tissue-contacting plate 224 defines a longitudinally-extending knife channel 225 extending at least partially therethrough and may include one or more stop members, similarly as with jaw member 210 (FIG. 3B). Insulative housing 226 of jaw member 220 is similar to that of jaw member 210 (FIG. 3B) and, thus, the features thereof will not be repeated here.

As illustrated in FIGS. 1 and 3A-4B, jaw members 210, 220 taper in height and width from the proximal ends to the distal ends thereof, thus facilitating blunt dissection and inhibiting jaw splay. Jaw members 210, 220 also define curved configurations that facilitate visualization of the surgical site and provide increased surface area for grasping tissue.

With reference to FIGS. 5A-5B, distal clevis portion 125 c of inner frame 124 of shaft member 120 and body plate 115 a of inner frame 114 of shaft member 110 are pivotably coupled to one another via pivot member 130 such that shaft members 110, 120 are movable relative to one another between spaced-apart and approximated positions to thereby pivot jaw members 210, 220 relative to one another between open and closed positions. More specifically, distal clevis portion 125 c and body plate 115 a define a lock-box configuration wherein distal clevis portion 125 c includes a bifurcated, U-shaped configuration having an elongated slot defined therein, and wherein body plate 115 a is configured for nested receipt within the elongated slot of the bifurcated, U-shaped distal clevis portion 125 c. Referring in particular to FIG. 5B, sufficient clearance is provided between distal clevis portion 125 c and body plate 115 a when body plate 115 a is nested within distal clevis portion 125 c such that lead wires 310 are permitted to extend therethrough, ultimately to electrically couple tissue-contacting plates 214, 224 (FIGS. 3B and 4B, respectively) to switch assembly 180 (FIGS. 1-2B) and the source of energy (not shown). Further, body 172 of knife lockout 170 is configured for positioning adjacent body plate 115 a within distal clevis portion 125 c to minimize lateral play between body plate 115 a and distal clevis portion 125 c and to act as a wire guide to maintain the lead wires 310 for jaw member 210 distally spaced-apart from pivot member 130. With respect to acting as a wire guide, body 172 of knife lockout 170 inhibits the lead wire 310 for jaw member 210 from interfering with and being damaged during the pivoting of shaft members 110, 120 about pivot member 130, and inhibits the lead wire 310 for jaw member 210 from interfering with and being damaged by translation of knife 140.

Referring also to FIGS. 5C-5D, pivot member 130 includes a body 132 and a cap 134. Body 132 of pivot member 130 is configured to extend through an aperture 125 e defined through one of the side walls of distal clevis portion 125 c of inner frame 124 of shaft member 120, pivot aperture 115 f of body plate 115 a of inner frame 114 of shaft member 110, and into a keyed aperture (or apertures) 125 f defined through the other side wall of distal clevis portion 125 c in fixed rotational orientation relative thereto. Body portion 132 of pivot member 130 is configured to be welded to the portion of the side wall of distal clevis portion 125 c that surrounds keyed aperture(s) 125 f. More specifically, the keying of body portion 132 within keyed aperture(s) 125 f maintains proper orientation of pivot member 130 during welding. Body 132 is further configured to abut stop protrusion 115 g (FIG. 3A) upon pivoting of shaft members 110, 120 away from one another to define a furthest-spaced apart position of shaft members 110, 120 and, similarly, a most-open position of jaw members 210, 220. A slot 136 defined through body 132 of pivot member 130 is configured to permit translation of knife 140 (FIGS. 9-10) therethrough, as detailed below.

Cap 134 of pivot member 130 defines a location recess 134′ therein, as illustrated in FIG. 5C, for example, although other configurations are also contemplated. Location recess 134′ is described below with respect to the assembly of forceps 100.

Turning to FIGS. 1 and 6-8, knife deployment mechanism 150 is coupled to shaft member 110 and generally includes a pair of opposed triggers 152 extending from either side of shaft member 110, first and second linkages 154, 156, and a biasing spring 158. Knife deployment mechanism 150 is disposed within outer housing 116 of shaft member 110 with the exception of opposed triggers 152 which extend from either side of outer housing 116. First linkage 154 is configured for positioning on one side of inner frame 114 of shaft member 110 and includes a pair of integral (or otherwise engaged) pivot bosses 161 extending from either side thereof at a first end portion of first linkage 154. One of the pivot bosses 161 extends through trigger aperture 115 d of inner frame 114 (see FIG. 3A). Each pivot boss 161 extends through an aperture defined through outer housing 116 of shaft member 110 to enable engagement of opposed triggers 152 therewith on either side of shaft member 110, e.g., via press-fitting, adhesion, or other suitable engagement.

Referring to FIGS. 6-8, a proximal end portion of second linkage 156 is pivotably coupled to first linkage 154 at a second end portion of first linkage 154. However, greater or fewer linkages 154, 156 are also contemplated. A distal end portion of second linkage 156 is pivotably coupled to knife 140 (see also FIGS. 9-10) via a pivot pin 163. Pivot pin 163 may be integrally formed with second linkage 156, e.g., as a post extending therefrom, or may be a separate component from second linkage 156. Pivot pin 163 extends transversely through longitudinal slot 115 e of inner frame 114 of shaft member 114 such that pivot pin 163 is constrained to longitudinal movement within longitudinal slot 115 e. Second linkage 156 is disposed on one side of inner frame 114, which may be the same side as first linkage 154 or the opposite side (as shown). In either configuration, pivot pin 163 extends from second linkage 156 and through longitudinal slot 115 e such that a portion of pivot pin 163 protrudes laterally from the opposite side of inner frame 114.

Biasing spring 158 may be configured as an extension spring or other suitable biasing spring 158 and is engaged at a distal end portion thereof to first linkage 154 and at a proximal end portion thereof to a support plate 166. Support plate 166 includes handle 118 of shaft member 110 integrally formed therewith or otherwise engaged thereto, and may be secured within outer housing 116 in any suitable fashion, e.g., via protrusion-aperture engagement. Support plate 166 provides increased structural support to shaft member 110 to inhibit splaying of shaft members 110, 120 during use. Shaft member 120 similarly includes a support plate 168 integrally formed with or otherwise engaging handle 128 of shaft member 120 and secured to outer housing 126, although support plate 168 need not extend distally as with support plate 166 (see FIGS. 2A and 2B).

Biasing spring 158 biases first linkage 154 towards a first orientation, corresponding to the un-actuated position of triggers 152 and the proximal-most position of second linkage 156, thereby biasing knife 140 towards the retracted position. Upon rotation of either of triggers 152 relative to shaft member 110, first linkage 154 is rotated against the bias of biasing spring 158 to thereby urge second linkage 156 distally such that pivot pin 163 is driven distally though longitudinal slot 115 e to urge knife 140 from the retracted position towards an extended position, wherein knife 140 extends through slot 136 of pivot member 130 and channels 215 a, 225 of jaw members 210, 220 (FIGS. 3B and 4B, respectively).

With reference to FIG. 18, another knife deployment mechanism 1150 configured for use with forceps 10 (FIG. 1) is shown. To the extent consistent, and except as specifically contradicted below, knife deployment mechanism 1150 may include any of the features of knife deployment mechanism 150, and vice versa. Knife deployment mechanism 1150 includes a pair of opposed triggers (not shown) extending from either side of shaft member 110, first, second, and third linkages 1154, 1155, 1156, respectively, and a biasing spring 1158.

Knife deployment mechanism 1150 is disposed within outer housing 116 of shaft member 110 with the exception of the opposed triggers which extend from either side of outer housing 116. First linkage 1154 is configured for positioning on one side of inner frame 114 of shaft member 110 and includes a pair of integral (or otherwise engaged) pivot bosses 1161 extending from either side thereof at a first end portion of first linkage 1154. One of the pivot bosses 1161 extends through inner frame 114 and each pivot boss 1161 extends through an aperture defined through outer housing 116 of shaft member 110 to enable engagement of the opposed triggers thereon.

A proximal end portion of second linkage 1155 is pivotably coupled to first linkage 1154 at a second end portion of first linkage 1154 and a distal end portion of second linkage 1155 is pivotably coupled to a proximal end portion of third linkage 1156 via a pivot pin 1159. Either or both ends of pivot pin 1159 are received within an arcuate track 1160 defined on the interior surface of either or both sides of outer housing 116. Third linkage 1156 is pivotably coupled to knife 140 at a distal end of third linkage 1156.

Biasing spring 1158 may be configured as an extension spring and is engaged at a distal end portion thereof to first linkage 1154 and is fixed within shaft member 110 at a proximal end portion thereof so as to bias first linkage 1154 towards a first orientation, corresponding to the un-actuated position of the triggers and the proximal-most position of second and third linkages 1155, 1156, thereby biasing knife 140 towards the retracted position.

Upon rotation of either of the triggers relative to shaft member 110, first linkage 1154 is rotated against the bias of biasing spring 1158 to thereby urge second linkage 1556 distally (urging pivot pin 1159 distally through arcuate track 1160) to thereby urge third linkage 1156 distally such knife 140 is driven distally from the retracted position towards the extended position.

With reference to FIG. 19, yet another knife deployment mechanism 2150 configured for use with forceps 10 (FIG. 1) is shown. To the extent consistent, and except as specifically contradicted below, knife deployment mechanism 2150 may include any of the features of knife deployment mechanism 150, and vice versa. Knife deployment mechanism 2150 includes a pair of opposed triggers 2152 (only one of which is shown in FIG. 19) extending from either side of shaft member 110, first second, and third linkages 2154, 2155, 2156, respectively, and a biasing spring (not shown).

Knife deployment mechanism 2150 is disposed within outer housing 116 of shaft member 110 with the exception of opposed triggers 2152 which extend from either side of outer housing 116. First linkage 2154 includes a pair of integral (or otherwise engaged) pivot bosses 2161 extending from either side thereof at a first end portion of first linkage 2154. Pivot bosses 2161 extend through apertures defined through outer housing 116 of shaft member 110 to enable engagement of opposed triggers 2152 thereon.

A proximal end portion of second linkage 2155 is coupled to first linkage 2154 at a second end portion of first linkage 2154 via a pin-slot engagement 2159. A distal end portion of second linkage 2155 is pivotably coupled to a proximal end portion of third linkage 2156. Third linkage 2156 is pivotably coupled to knife 140 at a distal end of third linkage 2156. The biasing spring is configured to bias first linkage 2154 towards a first orientation, corresponding to the un-actuated position of triggers 2152 and the proximal-most position of second and third linkages 2155, 2156, thereby biasing knife 140 towards the retracted position.

Upon rotation of either of triggers 2152 relative to shaft member 110, first linkage 2154 is rotated against the bias of the biasing spring to thereby urge second linkage 2155 distally (as the pin of pin-slot engagement 2159 is pivoted and slid through the slot of pin-slot engagement 2159), to thereby urge third linkage 1156 distally such knife 140 is driven distally from the retracted position towards the extended position.

Referring generally to FIGS. 18 and 19, knife deployment mechanisms 1150, 2150 are advantageous in that, by utilizing three linkages in the configurations detailed above, they allow for a reduced height of shaft member 110, thus facilitating a surgeon's visualization into the surgical site.

Referring to FIGS. 9 and 10, knife 140 includes a proximal body 142 defining an aperture 144 through which knife 140 is pivotably coupled to second linkage 156 of knife deployment mechanism 150 via pin 163 (see FIG. 6). Proximal body 142 is slidably disposed within channel 115 h between body plate 115 a and reinforcing plate 115 b of inner frame 114 of shaft member 110 (see FIG. 3A). Knife 140 further includes a distal body 146 defining a lower profile as compared to proximal body 142 and extending distally from proximal body 142. Distal body 146 defines a distal cutting portion 148. Distal cutting portion 148 defines an enlarged height as compared to distal body 146 and may be etched to define an asymmetrically sharpened configuration wherein one side of distal cutting portion 148 extends further distally than the opposite side (due to the removal of material from the opposite side during the etching process). The enlarged height of distal cutting portion 148 helps ensure that distal cutting portion 148 extends fully through the gap defined between jaw members 210, 220 (FIG. 1) and is at least partially received in respective knife channels 215 a, 225 thereof (see FIGS. 3B and 4B). In the retracted position of knife 140, the enlarged height of distal cutting portion 148 is configured for receipt within a roof 213 defined by a proximally-extending portion of jaw support 212 of jaw member 210 (see FIG. 3A). The etched distal cutting edge of distal cutting portion 148 defines three segments: a main cutting segment 149 a, a lower cutting segment 149 b extending from one end of main cutting segment 149 a at an angle relative thereto, and an upper cutting segment 149 c extending from the opposite end of main cutting segment 149 a at an angle relative thereto.

Knife 140 further includes a partial etch 149 d extending along a portion of distal body 146 and distal cutting portion 148 of knife 140. Partial etch 149 d may extend along either or both sides of knife 140. Partial etch 149 d is configured to inhibit wear of knife 140, to promote flexibility to facilitate translation of knife 140 through knife channels 215 a, 225 of jaw members 210, 220 (see FIGS. 3A-4B), to facilitate smooth translation of knife 140 through knife channels 215 a, 225 (see FIGS. 3A-4B) should partial etch 149 d come in contact with the sidewalls defining channels 215 a, 225 (see FIGS. 3A-4B), and to provide greater clearance between knife 140 and the sidewalls defining channels 215 a, 225 (see FIGS. 3A-4B).

In use, distal body 146 of knife 140 is configured to reciprocate through slot 136 of pivot member 130 (FIG. 5D) to translate distal cutting edge 148 through knife channels 215 a, 225 of jaw members 210, 220 in response to actuation of either of triggers 152 (see FIGS. 2A-4B). Knife 140 further includes a stop shoulder 147 defined at the transition between proximal body 142 and distal body 146. Stop shoulder 147 defines a height greater than a height of slot 136 of pivot member 130 (FIG. 5D) such that stop shoulder 147 is inhibited from passing therethrough. Accordingly, stop shoulder 147 defines the distal-most extent of travel of knife 140, e.g., wherein stop shoulder 147 abuts pivot member 130 (FIG. 5D). Alternatively, rather than abutting pivot member 130, stop shoulder 147 may abut a portion of distal clevis portion 125 c defining keyed aperture(s) 125 f for similar purposes.

Referring to FIGS. 20A-25B, knives 1140, 2140, 3140, 4140, 5140, 6140 having various different configurations of the distal body 1146, 2146, 3146, 4146, 5146, 6146, respectively, are illustrated and detailed below. Knives 1140, 2140, 3140, 4140, 5140, 6140, more specifically, are configured to promote flexibility to facilitate translation through the curved knife channels 215 a, 225 of curved jaw members 210, 220 (see FIGS. 3A-4B) and to inhibit contact with, wear of, and damage to channels 215 a, 225 (see FIGS. 3A-4B) and knives 1140, 2140, 3140, 4140, 5140, 6140. The distal body 1146, 2146, 3146, 4146, 5146, 6146 of each knife 1140, 2140, 3140, 4140, 5140, 6140 defines a respective outer side surface 1147 a, 2147 a, 3147 a, 4147 a, 5147 a, 6147 a (e.g., the sides on the outside of the curve through which the knives travel, facing the concave sides of the knife channels) and a respective inner side surface 1147 b, 2147 b, 3147 b, 4147 b, 5147 b, 6147 b (e.g., the sides on the inside of the curve through which the knives travel, facing the convex sides of the knife channels). To the extent consistent, any of the features of 1140, 2140, 3140, 4140, 5140, 6140 may be used in conjunction with one another in any suitable combination.

Distal body 1146 of knife 1140, as illustrated in FIGS. 20A and 20B, includes outer side surface 1147 a and inner side surface 1147 b. Inner side surface 1147 b is flat (within manufacturing tolerances), as illustrated in FIG. 20B. Outer side surface 1147 a includes a first etching forming an etched distal cutting edge 1148, similarly as detailed above with respect to knife 140 (FIGS. 9 and 10). Outer side surface 1147 a further includes a second, partial etching 1149 such that outer side surface 1147 a includes a relatively protruded surface portion 1149 a and a relatively recessed surface portion 1149 b. As a result of the second, partial etching 1149, the relatively protruded surface portion 1149 a includes a tapered proximal section that tapers down in height from the full height of body 1146 of knife 1140 in a proximal-to-distal direction, and a constant height (within manufacturing tolerances) distal section extending from the distal end of the tapered proximal section. The constant height distal section of the relatively protruded surface portion 1149 a extends to the distal cutting portion of knife 1140 but remains spaced from etched distal cutting edge 1148. The distal end of the constant height section of the relatively protruded surface portion 1149 a is rounded to eliminate sharp edges.

Distal bodies 2146, 3146 of knives 2140, 3140 (FIGS. 21A-21B and 22A-22B, respectively), are similar to distal body 1146 of knife 1140. The second, partial etches 2149, 3149 may be configured such that relatively protruded surface portions 2149 a, 3149 a define different tapered proximal portion lengths, different tapered proximal portion slopes, different constant height distal portion lengths, and/or different constant height distal portion heights as compared to those of distal body 1146 of knife 1140. Further, outer side surface 2147 a of distal body 2146 of knife 2140 includes a laser-polished tip portion 2148. The first etching of distal body 3146 of knife 3140, on the other hand, defines a sharpened point 3148 b within distal cutting edge 3148 a.

Referring to FIGS. 23A-23B, distal body 4146 of knife 4140 includes outer and inner side surfaces 4147 a, 4147 b, which include second, partial etchings 4149 a, 4149 b of generally similar configuration. For example, outer side surface 4147 a defines second, partial etching 4149 a such that the relatively protruded surface portion thereof defines a U-shaped configuration oriented such that the uprights of the U-shape extend longitudinally, the closed end of the U-shape is disposed proximally, and the open end of the U-shape is disposed distally. Inner side surface 4147 b defines second, partial etching 4149 b such that the relatively protruded surface portion thereof defines a U-shaped configuration oriented such that the uprights of the U-shape extend longitudinally, the closed end of the U-shape is disposed proximally, and the open end of the U-shape is disposed distally. However, second, partial etching 4149 a stops before reaching the distal cutting portion of knife 4140, while second partial etching 4149 b extends about an outer perimeter of the distal cutting portion of knife 4140, surrounding a relatively protruded surface portion peninsula at the distal cutting portion of knife 4140. Distal cutting edge 4148, formed via a first etching on outer side surface 4147 a, may further include a stepped portion to define a radiused (or more radiused) lower distal corner of distal cutting edge 4148. In other embodiments, the lower distal corner of distal cutting edge 4148 is radiused without a stepped portion. Alternatively, rather than a radiused lower distal corner, the distal cutting edge may meet a flat lower edge, such as illustrated in FIGS. 20A, 21A, and 25A.

Referring to FIGS. 24A-24B, distal body 5146 of knife 5140 includes outer and inner side surfaces 5147 a, 5147 b, which include second, partial etchings 5149 a, 5149 b of generally similar configuration. For example, outer side surface 5147 a defines second, partial etching 5149 a wherein the relatively protruded surface portion includes a tapered proximal section that tapers down in height in a proximal-to-distal direction, and a constant height (within manufacturing tolerances) distal section extending from the distal end of the tapered proximal section and terminating at the distal cutting portion of knife 5140 but spaced-apart from the distal cutting edge thereof. Inner side surface 5147 b defines second, partial etching 5149 b wherein the relatively protruded surface portion includes a tapered proximal section that tapers down in height in a proximal-to-distal direction, and a constant height (within manufacturing tolerances) distal section extending to the distal cutting portion of knife 5140. However, second, partial etching 5149 b is fully etched at the distal cutting portion of knife 5140, rather than terminating at the distal cutting portion spaced-apart from the distal cutting edge.

FIGS. 25A and 25B illustrate knife 6140 including distal body 6146 having outer and inner side surfaces 6147 a, 6147 b, which include second, partial etchings 6149 a, 6149 b. Second partial etchings 6149 a, 6149 b similarly extend along a distal portion of distal body 6146, the entire height thereof, except that inner side surface 6147 a includes a distal portion that is not etched, so as to define a relatively protruded surface portion 6149 c that opposes and is shaped similarly to distal cutting edge 6148, which is etched at the distal end of outer side surface 6147 a.

Referring to FIGS. 26A and 26B, a distal portion 7146 of another knife 7140 configured to promote flexibility to facilitate translation through the curved knife channels 215 a, 225 of curved jaw members 210, 220 (see FIGS. 3A-4B) and to inhibit contact with, wear of, and damage to channels 215 a, 225 (see FIGS. 3A-4B) and knife 7140 is shown. Knife 7140 may include any of the features of any of the knives detailed above. Distal portion 7146 of knife 7140 further includes a plurality of transverse apertures 7147 extending therethrough. Apertures 7147 are spaced-apart along at least a portion of the length of distal portion 7146 of knife 7140. Apertures 7147 increase the flexibility of distal portion 7146 of knife 7140, thus facilitating translation of knife 7140 through the curved knife channels 215 a, 225 of curved jaw members 210, 220 (see FIGS. 3A-4B).

Turning to FIGS. 27A and 27B, a distal portion 8146 of another knife 8140 configured to promote flexibility to facilitate translation through the curved knife channels 215 a, 225 of curved jaw members 210, 220 (see FIGS. 3A-4B) and to inhibit contact with, wear of, and damage to channels 215 a, 225 (see FIGS. 3A-4B) and knife 8140 is shown. Distal portion 8146 includes an outer side surface 8147 a and inner side surface 8147 b. Inner side surface 8147 b is flat (within manufacturing tolerances), although other configurations are also contemplated. Outer side surface 8147 a includes a first etching forming an etched distal cutting edge 8148, similarly as detailed above with respect to knife 140 (FIGS. 9 and 10). Outer side surface 8147 a further includes a second, partial etching 8149 forming a plurality of alternating relatively protruded surface strips 8149 a and relatively recessed surface strips 8149 b along at least a portion of the length of distal portion 8146. Second, partial etching 8149 thus forms alternating relatively thicker and thinner sections of distal portion 8146 along at least a portion of the length of distal portion 8146, which increases the flexibility of distal portion 8146 of knife 8140, thus facilitating translation of knife 8140 through the curved knife channels 215 a, 225 of curved jaw members 210, 220 (see FIGS. 3A-4B).

With momentary reference to FIGS. 1 and 2A, knife deployment mechanism 150 is operably positioned on shaft member 110 and relative to shaft member 120 such that such that triggers 152 do not extend beyond the height dimension of forceps 100 in the vicinity of triggers 152, even in the furthest-approximated position of shaft members 110, 120. As a result of this configuration, forceps 100 benefits from a low-profile design that inhibits triggers 152 from catching on the surgeon, patient, or on nearby objections during use and/or as forceps 100 is inserted and withdrawn from the surgical site.

Referring to FIGS. 11A-13, in some embodiments, each trigger 152′ may be provided with a non-circular aperture 153 a′ configured to receive a correspondingly-shaped pivot boss (not shown) of first linkage 154′ (FIG. 13). In such embodiments, each trigger 152′ may further include a pair of opposed cantilever arms 153 b′ extending from opposite sides of non-circular aperture 153 a′. As detailed below, cantilever arms 153 b′ include fingers 153 c′ configured to operably engage outer housing 116′ to retain triggers 152′ in engagement with first linkage 154′ (FIG. 13) without the need for press-fitting.

With reference to FIG. 11B, in order to operably engage triggers 152′, outer housing 116′ defines a pair of opposed apertures 118′ (only one of which is shown) defining a pair of cut-outs 119 a′. Outer housing 116′ further includes a stop protrusion 119 b′ on an inner surface thereof adjacent each cut-out 119 a′.

Referring to FIGS. 12A and 12B, in order to engage triggers 152′ with outer housing 116′, triggers 152′ are oriented such that non-circular apertures 153 a′ are aligned relative to the correspondingly-shaped pivot bosses (not shown) and such that cantilever arms 153 b′ are aligned relative to cut-outs 119 a′. Thereafter, triggers 152′ are advanced such that the pivot bosses (not shown) are received within non-circular apertures 153 a′ and such that cantilever arms 153 b′ extend sufficiently through cut-outs 119 a′ and into outer housing 116′ such that fingers 153 c′ are disposed internally of outer housing 116′. Once this position has been achieved, triggers 152′ are rotated relative to outer housing 126 such that fingers 153 c′ are no longer aligned with cut-outs 129 a′ and, accordingly, such that triggers 152′ are inhibited from backing out of apertures 128′. Thereafter, first linkage 154′ is coupled to the other components of the knife deployment mechanism, e.g., similarly as detailed above. This engagement of first linkage 154′ with the other components defines a range of motion of first linkage 154′ and, more specifically, limits the range of motion thereof such that, in conjunction with stop protrusions 119 b′, first linkage 154′ inhibits triggers 152′ from rotating back to a position wherein cantilever arms 153 b′ are aligned relative to cut-outs 119 a′. Thus, disengagement of triggers 152′ from outer housing 116′ and first linkage 154′ are inhibited without requiring press-fit, adhesion, or other backout-preventing engagement between triggers 152′ and first linkage 154′.

Turning to FIGS. 1, 2A, and 14, knife lockout 170 works in conjunction with shaft members 110, 120 to inhibit deployment of knife 140 prior to shaft members 110, 120 reaching a sufficiently-approximated position corresponding to a sufficiently-closed position of jaw members 210, 220. Knife lockout 170 includes a body 172 that is disposed about a portion of the inner frame 114 of shaft member 110 and forms a portion of outer housing 116 of shaft member 110. More specifically, as shown in FIG. 1, body 172 of knife lockout 170 defines a complementarily-shaped abutting surface with the abutting surface of the adjacent other component(s) of housing 116 such that housing 116 defines a substantially continuous outer surface. Body 172 extends at least partially within U-shaped distal clevis portion 125 c of shaft member 110 to inhibit excess lateral play therebetween, as noted above.

Referring to FIG. 14, knife lockout 170 further includes a cantilever arm 174 extending proximally from body 172. Cantilever arm 174 and body 172 may be integrally formed, e.g., via injection molding, or may be attached in any other suitable fashion. Cantilever arm 174 extends along inner frame 114 of shaft member 110 on an opposite side of inner frame 114 as compared to second linkage 156 of knife deployment mechanism 150. Cantilever arm 174 defines a relatively narrowed configuration to permit flexing of cantilever arm 174. A finger 176 integrally formed with cantilever arm 174 extends generally perpendicularly from a free end of cantilever arm 174 and through an opening defined in outer housing 116 of shaft member 110 towards shaft member 120. A nook 178 is defined at the junction of cantilever arm 174 and finger 176. A stop 179 protrudes from cantilever arm 174 in the vicinity of nook 178 and defines an angled distal wall 179 a and a vertical proximal wall 179 b that, together with cantilever arm 174 and finger 176, enclose a portion of nook 178.

With shaft members 110, 120 sufficiently spaced-apart from one another, finger 176 of knife lockout 170 is spaced-apart from outer housing 126 of shaft member 120 such that cantilever arm 174 is disposed in its at-rest position. In the at-rest position, cantilever arm 174 extends along and in generally parallel orientation relative to longitudinal slot 115 e of inner frame 114 of shaft member 110. Further, nook 178 is disposed at the proximal end of longitudinal slot 115 e and receives the portion of pivot pin 163 that extends from second linkage 156 through longitudinal slot 115 e therein. As such, vertical proximal wall 179 b of stop 179 inhibits distal advancement of pivot pin 163 in the at-rest position of cantilever arm 174 and, accordingly, inhibits deployment of knife 140.

In order to disengage knife lockout 170 to permit deployment of knife 140, shaft members 110, 120 are sufficiently approximated such that a portion of outer housing 126 of shaft member 120 contacts finger 176 of knife lockout 170 and urges finger 176 further into housing 116 of shaft member 110. As finger 176 is urged further into housing 116, cantilever arm 174 is flexed such that nook 178 is withdrawn from about pivot pin 163 and vertical proximal wall 179 b of stop 179 is removed from the path of pivot pin 163. Once this has been achieved, knife deployment mechanism 150 may be actuated, as detailed above, to advance pivot pin 163 distally through slot 115 e to deploy knife 140 from the retracted position towards the extended position.

Should shaft members 110, 120 be moved apart from one another sufficiently such that shaft member 120 no longer urges finger 176 to flex cantilever arm 174, cantilever arm 174 is resiliently returned to its at-rest position. If knife 140 is disposed in the retracted position at this point, nook 178 is returned to surrounding engagement about pivot pin 163. However, if knife 140 is disposed in the deployed position or a partially-deployed position, the return of cantilever arm 174 to its at-rest position does not re-capture pivot pin 163. Rather, upon subsequent return of knife 140 to the retracted position, pivot pin 163 is moved proximally and into contact with angled distal wall 179 a of stop 179, camming therealong and urging cantilever arm 174 to flex from the at-rest position sufficiently so as to enable pivot pin 163 to return to the proximal end of longitudinal slot 115 e. Once pivot pin 163 reaches this position, cantilever arm 174 is returned to the at-rest position and, as a result, nook 178 is returned to surrounding engagement about pivot pin 163, thereby locking-out knife 140 until shaft members 110, 120 are once again sufficiently approximated. The biasing force of biasing member 158 is sufficient to move pivot pin 163 proximally to deflect cantilever arm 174 and reset knife lockout 170 as detailed above. As such, resetting of knife lockout 170 occurs automatically (if shaft members 110, 120 are sufficiently spaced-apart) upon return of knife 140 to the retracted position.

With reference to FIGS. 2A, 3B, 3A, 4A, and 15, the above-detailed structural support features of shaft members 110, 120 inhibit splaying of shaft members 110, 120 during use, e.g., in the directions of arrows “S” (FIG. 15). More specifically, reinforcing plate 115 b of inner frame 114, enlarged body portion 125 a of inner frame 124, support plates 166, 168 (that retain handles 118, 128), and the lockbox configuration of shaft members 110, 120 all add structural support to shaft members 110, 120 to inhibit splaying of shaft members 110, 120 during use. Further, the positioning of knife 140 within channel 115 h between body plate 115 a and reinforcing plate 115 b inhibits splay of knife 140 during use.

Turning to FIGS. 16A and 16B, switch assembly 180 is disposed on shaft member 120 and generally includes an activation button 182 and a Printed Circuit Board (PCB) 184. Activation button 182 includes a button housing 183 a and a depressible button 183 b. Depressible button 183 b is configured to be contacted by the outer housing 116 of shaft member 110 upon sufficient approximation of shaft members 110, 120 so as to depress depressible button 183 b and activate switch assembly 180. With additional reference to FIGS. 1-2B, as noted above, the position of shaft members 110, 120 wherein switch assembly 180 is activated, together with the flexion of inner frame 124, enable application of a particular jaw force, or jaw force within a particular range, to tissue grasped between jaw members 210, 220.

PCB 184 of switch assembly 180 includes a board body 185 defining a first end portion 186 a, a second end portion 186 b, and a central portion 186 c. Central portion 186 c of board body 185 is configured to receive activation button 182 thereon. More specifically, central portion 186 c defines apertures 187 a (or other suitable engagement features) to enable snap-fitting (or other suitable mechanical engagement) of activation button 182 thereon. Central portion 186 c further defines circuit traces 187 b such that, upon mechanical engagement of activation button 182 thereon, activation button 182 is also electrically coupled to PCB 184. This configuration facilitates assembly and reduces the possibility of improper connections. Circuit traces 187 b extend from central portion 186 c towards first end portion 186 a of board body 185 on both the upper and lower faces of board body 185 to enable connection of a pair of lead wires 310 (only one of which is shown) of electrosurgical cable 300 thereto, e.g., via soldering. Circuit traces 187 b also extend from central portion 186 c towards second end portion 186 b of board body 185 on both the upper and lower faces of board body 185. A quick-connect receptacle 188 is disposed on each of the upper and lower faces of body board 185 towards second end portion 186 b thereof in electrical communication with circuit traces 187 b. Quick-connect receptacles 188 facilitate engagement of lead wire receptacles 189 (only one of which is shown) therewith, thus facilitating coupling of the lead wires 310 of jaw members 210, 220 with switch assembly 180. More specifically, lead wire receptacles 189 are configured to slide into snap fit or other suitable engagement with quick-connect receptacles 188 to both mechanically engage lead wire receptacles 189 with PCB 184 and electrically couple the lead wires 310 of jaw members 210, 220 to corresponding portions of circuit traces 187 b. As a result of the above-detailed configuration of switch assembly 180, activation of activation button 182 initiates the supply of energy from the energy source (not shown) to jaw members 210, 220 such that such energy may be conducted through tissue grasped between tissue-contacting plates 214, 224 of jaw members 210, 220 to treat tissue (see FIGS. 3A-4B).

Referring to FIGS. 17A-17H, the assembly of forceps 100 is detailed. In detailing the assembly of forceps 100 hereinbelow, additional structural features and functional benefits of forceps 100 may be described and/or become apparent. Accordingly, despite being described in connection with the assembly of forceps 100, the features of forceps 100 detailed herein (above or below) are not limited to assembly in the manner detailed below. Likewise, the advantageous order and manner of assembly of the components of forceps 100 as detailed below is not limited to use with the particular features of the various components of forceps 100 detailed above or otherwise herein.

With initial reference to FIGS. 17A and 17B, inner frames 114, 124 of shaft members 110, 120 are pre-assembled with the respective jaw members 210, 220 thereon, as detailed above. Switch assembly 180 is also pre-assembled together with electrosurgical cable 300, as also detailed above. With inner frames 114, 124 pre-assembled with jaw members 210, 220, respectively, knife 140 may then be operably coupled to inner frame 114 of shaft member 110 such that knife 140 extends through longitudinal channel 115 h of inner frame 114 and aperture 144 of knife 140 is aligned with longitudinal slot 115 e of inner frame 114. Thereafter, shaft members 110, 120 are aligned to enable pivot member 130 to be inserted through aperture 125 e of distal clevis portion 125 c of inner frame 124, pivot aperture 115 f of body plate 115 a of inner frame 114, and into keyed aperture(s) 125 f defined through the other side wall of distal clevis portion 125 c. Upon such positioning, slot 136 of pivot member 130 receives a portion of knife 140. Body portion 132 of pivot member 130 may be welded, e.g., via laser welding, to the portion of the side wall of distal clevis portion 125 c that surrounds keyed aperture(s) 125 f at this point or later on during the assembly process. Location recess 134′ of cap 134 of pivot member 130 (see FIG. 5C) is utilized during welding of pivot member 130 to distal clevis portion 125 c, obviating the need to utilize a vision system to enable precise welding. Location recess 134′ further serves as a “zero” position during component assembly, welding (as mentioned above in addition to other welding) and other fixation, and testing, e.g., jaw force testing, jaw gap testing, and electrical testing.

Turning to FIG. 17C, with inner frames 114, 124 of shaft members 110, 120 operably coupled to one another via pivot member 130 and with knife 140 operably coupled to inner frame 114, a portion of outer housing 126 of shaft member 120 is positioned on inner frame 124 and the lead wires 310 of jaw members 210, 220 are routed therethrough. Once routed through the portion of outer housing 126 installed on inner frame 124, the lead wires 310 of jaw members 210, 220 are operably coupled to switch assembly 180 via connection of lead wire receptacles 189 with quick-connect receptacles 188 of switch assembly 180, thereby electrically coupling jaw members 210, 220 with switch assembly 180 and electrosurgical cable 300. Additionally, at this point, knife lockout 170 is installed on inner frame 114 of shaft member 110.

With reference to FIG. 17D, handles 118, 128 are engaged within first half-housing portions of outer housings 116, 126 of shaft members 110, 120, respectively, although handles 118, 128 may alternatively be pre-assembled with the first half-housing portions of outer housing 116, 126. First linkage 154 of knife deployment mechanism 150 is then operably positioned such that one of the pivot bosses 161 thereof extends through a corresponding aperture defined through the first half-housing portion of outer housing 116. Thereafter, biasing member 158 is operably coupled between first linkage 154 and handle 118, as detailed above. The trigger 152 corresponding to the first half-housing portion of outer housing 116 is also engaged about the portion of the pivot boss 161 that extends outwardly from the first half-housing portion of outer housing 116.

Referring to FIG. 17E, the subassembly of FIG. 17C and the subassembly of FIG. 17D are combined. More specifically, inner frames 114, 124 are operable engaged within the respective first half-housing portions of outer housing 116, 126. Further, switch assembly 180 and the distal end of electrosurgical cable 300 are seated within the first half-housing portion of outer housing 126 of shaft member 120.

Turning to FIG. 17F, once the subassemblies of FIGS. 17C and 17D are combined as noted above, second linkage 156 of knife deployment assembly 150 is engaged to first linkage 154 and knife 140 (through inner frame 114 of shaft member 110). With the internal components of forceps 100 in place, the second half-housing portions of outer housing 116, 126 are moved into place to fully form outer housings 116, 126 and enclose the internal components therein, as illustrated in FIG. 17G. Finally, as shown in FIG. 17H, the other trigger 152 of knife deployment mechanism 150 is engaged with the corresponding pivot boss 161 of first linkage 154 on the second half-housing side of outer housing 116 of shaft member 110.

Once assembly is completed, e.g., as detailed above, testing may be performed to ensure proper operation of forceps 100. Such testing may include jaw force testing; testing using a gauge pin (not shown) to test the maximum jaw aperture between jaw members 210, 220 at the distal tips thereof; cut testing of the knife 140 using cut test media (not shown); testing of the gap distance between the tissue-contacting plates 214, 224 of jaw members 210, 220 (as set by the one or more stop members 215 b and/or beak sections 218 c of jaw members 210, 220) in the approximated position thereof at various positions along the lengths of jaw members 210, 220; and/or performing electrical continuity testing.

Referring to FIG. 17H, forceps 100, once fully assembled, defines a first length “L1” extending distally from the midpoint of pivot member 130 to the distal end of distal tip of jaw members 210, 220 (FIG. 1) of end effector assembly 200 and a second length “L2” extending proximally from the midpoint of pivot member 130 to the midpoint of handles 118, 128. A ratio L2:L1 of the second length to the first length is from about 2.0 to about 4.0 to provide the surgeon with an expected feel. More specifically, a ratio L2:L1 ranging from about 2.0 to about 4.0 has been found to correspond to an expected feel such that when a surgeon pivots handles 118, 128 towards or away from one another, jaw members 210, 220 (FIG. 1) are pivoted relative to one another an expected amount or close thereto. Ratios outside this range may require that the surgeon learn the device to achieve desired movement of the jaw members 210, 220 (FIG. 1), whereas forceps 100 provides an expected feel without the need for, or minimal, learning. As an example without limitation, length “L1” may be about 4 cm and length “L2” may be about 14 cm, thereby providing a ratio L2:L1 of 3.5.

Turning now to FIGS. 28-30, forceps 100 is configured to facilitate tissue treatment, tissue division, and blunt tissue dissection. In particular, the various geometries, properties, and ratios of the features of forceps 100, as detailed below, are provided such that forceps 100 facilitates tissue treatment, tissue division, and blunt tissue dissection. More specifically, these features provide forceps 100 with long, fine, curved jaw members that allow for precision when working in and around critical tissue structures and other tight spaces, maximize line of sight, enable fine blunt tissue dissection, enable tissue division closer to the distal tip of forceps 100, and reduce cooling times after energy application, all while providing reliable tissue seals. To the extent consistent, the aspects and features of the jaw members of forceps 100 detailed herein may likewise be utilized in conjunction with a shaft-based (endoscopic or open) surgical forceps, a robotic surgical forceps, or other suitable style instrument.

Referring in particular to FIG. 28, it has been found that the above may be achieved by providing each jaw member with appropriate tip geometry ratio(s). As the distal tip portions of both jaw members are designed the same, FIG. 28 only illustrates, and reference is only made herein to, distal tip portion 280 of jaw member 220, keeping in mind that the geometry ratio(s) of tip portion of jaw member 210 (FIG. 1) are the same (taking into account tolerances).

As illustrated in FIG. 28, jaw member 220 includes a distal tip portion 280. Distal tip portion 280 of jaw member 220, in embodiments, is the area defined within the concave side of a curved distal perimeter of jaw member 220 (as viewed from the top or bottom of jaw member 220). More specifically, distal tip portion 280 may be defined as the portion of jaw member 220 encompassed by the half-ellipse “E” at the distal end of jaw member 220 (as viewed from the top or bottom of jaw member 220). In such embodiments, distal tip portion 280 has a curved distal perimeter 282 that defines the outer periphery of distal tip portion 280 (and the half circumference defined by the half-ellipse “E”), a full diameter 284 which serves as a dividing line between distal tip portion 280 of jaw member 220 and the rest of jaw member 220, and a half-diameter or radius 286 (owing to the fact that tip portion 280 is a half-ellipse rather than a full ellipse). Full diameter 284 is the minor diameter of the half-ellipse “E” and also defines the width dimension of distal tip portion 280 of jaw member 220, as distal tip portion 280 tapers distally of full diameter 284 to a blunt distal end defined by curved distal perimeter 282. Radius 286 is the major radius of the half-ellipse “E.”

A width to length ratio of distal tip portion 280 is, in embodiments, from about 1.45 to about 1.70, in other embodiments, from about 1.50 to about 1.65 and, in still other embodiments, from about 1.55 to about 1.60. In other embodiments, the ratio is about 1.57. The width dimension “W1” of distal tip portion 280 is the largest width of distal tip portion 280 defined transversely across jaw member 220 and, thus, is defined by full diameter 284. The length dimension “L3” of distal tip portion 280 is defined longitudinally along jaw member 220 and, thus, is defined by radius 286, which extends from full diameter 284 to the distal end of jaw member 220. Thus, in embodiments, the above ratio ranges may likewise apply to the ratio of the full diameter of the half-ellipse “E” of distal tip portion 280 to the radius of the half-ellipse “E” of distal tip portion 280. The use of “about” with respect to the above-noted ratios and otherwise herein accounts for generally accepted manufacturing, use, environmental, and measurement tolerances.

Referring also to FIG. 30, a height to length ratio of jaw members 210, 220 at the distal tip portions 280 thereof may be utilized together with or separately from the above-noted width to length ratios. The height to length ratio may be, in embodiments, from about 2.25 to about 2.55, in other embodiments, from about 2.30 to about 2.50 and, in still other embodiments, from about 2.35 to about 2.45. In other embodiments, the ratio is about 2.40. The length dimension “L3” is the length of the distal tip portion 280 of jaw member 220 (or likewise of jaw member 210, which is the same absent tolerances), as detailed above. The height dimension “H1” is the height defined collectively by jaw members 210, 220 at the distal tip portions 280 (more specifically, at full diameter 284 of distal tip portion 280) thereof when jaw members 210, 220 are disposed in the fully closed position, e.g., wherein a gap distance defined between the distal tip portions 280 of jaw members 210, 220 is equal to or less than about 0.003 inches. In other embodiments, the gap distance is equal to or less than about 0.025 inches; in yet other embodiments, the gap distance is equal to or less than about 0.020 inches; in still other embodiments, the gap distance is equal to or less than about 0.015 inches; and in still yet other embodiments, the gap distance is equal to or less than about 0.010 inches. In embodiments, the distal tip portions 280 of jaw members 210, 220 may contact one another in the fully closed position, eliminating a minimum gap distance therebetween.

Turning to FIGS. 28-29, it has been found that facilitating tissue treatment, tissue division, and blunt tissue dissection may additionally or alternatively be achieved by providing each jaw member with appropriate curvature and/or taper geometry ratio(s). As the tip portions of both jaw members are designed the same, FIG. 29 only illustrates, and reference is only made herein to, tip portion 280 of jaw member 220, keeping in mind that the geometry ratio(s) of tip portion of jaw member 210 (FIG. 1) are the same.

Jaw member 220 defines a curvature along at least a portion of the length thereof and, more specifically, may include a proximal straight section 292 defining a longitudinal axis 294 and a distal curved section 296 that curves off of longitudinal axis 294. The proximal straight section 292 may define a length of about 0.0 inches to about 0.125 inches. Proximal straight section 292, in embodiments where provided, is centered about longitudinal axis 294 (at least as viewed from a top or bottom view of jaw member 220) and defines a substantially constant width “W2” (wherein the use of “substantially” herein accounts for generally accepted manufacturing, use, environmental, and measurement tolerances). This width “W2” is measured transversely across jaw member 220. A ratio of the width “W2” of proximal straight section 292 to the width “W1” of distal tip portion 280 (detailed above), in embodiments, is from about 1.60 to about 2.00, in other embodiments, from about 1.70 to about 1.90 and, in still other embodiments, from about 1.75 to about 1.85. In other embodiments, the ratio is about 1.80. In embodiments where no proximal straight section 292 is provided (i.e., where the proximal straight section 292 defines a length of 0.0 inches), the longitudinal axis 294 is defined longitudinally through the mid-point transversely across the proximal end of jaw member 220, e.g., across the proximal edge of the tissue-contacting plate 224 of jaw member 220. In such embodiments, the width “W2” is defined transversely across the proximal end of jaw member 220, e.g., across the proximal edge of the tissue-contacting plate 224 of jaw member 220, with the above-noted ratios applying similarly.

Distal curved section 296 of jaw member 220 defines a length “L4,” as measured along the longitudinal axis 294 from the position where jaw member 220 begins to curve to the position where a radius 286 of distal tip portion 280 (which symmetrically bisects distal tip portion 280) intersects curved distal perimeter 282 of distal tip portion 280. Distal curved section 296 further defines a distance of curvature “D1,” as measured transversely from the longitudinal axis 294 to the position where radius 286 of distal tip portion 280 meets curved distal perimeter 282 of distal tip portion 280. A ratio of the length “L4” of distal curved section 296 of jaw member 220 to the distance of curvature “D1” of distal curved section 296 of jaw member 220, in embodiments, is from about 2.40 to about 2.80, in other embodiments, from about 2.50 to about 2.70 and, in still other embodiments, from about 2.55 to about 2.65. In other embodiments, the ratio is about 2.60.

Turning momentarily to FIG. 31, tissue-contacting plate 224 of jaw member 220 is shown, although the following may additionally or alternatively apply to tissue-contacting plate 214 of jaw member 210 (FIGS. 3A-3B). As noted above, tissue-contacting plate 224 of jaw member 220 defines a longitudinally-extending knife channel 225. The distal curved section 296 of jaw member 220 defines an angle of curvature “θ,” in embodiments, from about 15 degrees to about 25 degrees; in other embodiments from about 17 degrees to about 23 degrees, in other embodiments from about 19 degrees to about 21 degrees; and in yet other embodiments, from about 19.5 degrees to about 20.5 degrees. In embodiments where jaw member 220 does not include a proximal straight portion 292 (FIG. 29) and, thus, distal curved section 296 of jaw member 220 constitutes the entirety of tissue-contacting plate 224, angle of curvature “θ” is defined between the longitudinal axis 294, which passes through a proximal transverse center point “A” of knife channel 225 at the proximal end of knife channel 225, and a line segment connecting proximal transverse center point “A” with a distal transverse center point “B.” Distal transverse center point “B” is transversely centered across the distal end of knife channel 225 and is disposed on the arcuate interior edge of tissue-contacting plate 224 that defines the closed distal end of knife channel 225. Alternatively, distal transverse center point “B” may be defined as the point at distal tip portion 280 of jaw member 220 where the half circumference defined by the half-ellipse “E” is intersected by the full diameter 284 (see FIGS. 28 and 29).

In embodiments where jaw member 220 includes a proximal straight portion 292, and, thus, distal curved section 296 of jaw member 220 constitutes only a portion of tissue-contacting plate 224, proximal transverse center point “A” of knife channel 225 is defined at the transverse line “T” dividing the proximal straight section 292 from the distal curved section 296 (see FIG. 29), with the above-detailed angles applying similarly.

With additional reference to FIG. 30, with respect to height taper of jaw members 210, 220, the ratio of proximal height to distal height is, in embodiments, from about 1.80 to about 2.10, in other embodiments, from about 1.85 to about 2.05 and, in still other embodiments, from about 1.90 to about 2.00. In other embodiments, the ratio is about 1.94. The proximal height “H2” is the height defined collectively by jaw members 210, 220 at the position where jaw member 210 emerges from distal clevis portion 125 c, as viewed from a side view of jaw members 210, 220, when jaw members 210, 220 are disposed in the fully closed position. The distal height “H1” is the height defined collectively by jaw members 210, 220 at the distal tip portions 280 (more specifically, at full diameter 284 of distal tip portion 280) thereof when jaw members 210, 220 are disposed in the fully closed position.

Referring still to FIG. 30, it has further been found that facilitating tissue treatment, tissue division, and blunt tissue dissection may be achieved by additionally or alternatively providing a ratio of the distance between the pivot and the proximal and distal ends of the lockbox configuration of shaft members 110, 120. More specifically, a ratio of the distance from the center of the pivot to the proximal end of the lockbox configuration “D3” to the distance from the center of the pivot to the distal end of the lockbox configuration “D2” is, in embodiments, from 0.90 to about 1.10, in other embodiments, from about 0.95 to about 1.05 and, in still other embodiments, from about 0.97 to about 1.01. In other embodiments, the ratio is from about 0.98 to about 0.99. The center of the pivot is defined as the center of pivot 130. The proximal end of the lockbox configuration is defined at the proximal end of the body of distal clevis portion 125 c, not including the proximal tail portion thereof. More specifically, the proximal end of the lockbox configuration is the position at which the proximally-facing edge of distal clevis portion 125 c changes slope, thus indicating the transition from the body of distal clevis portion 125 c to the proximal tail portion thereof. In other embodiments, the proximal end of the lockbox configuration is the distal end of inner frame 124 of shaft member 120, which extends within the proximal tail portion of distal clevis portion 125 c but does not extending into the body portion thereof. The distal end of the lockbox configuration is defined at the position where jaw member 210 emerges from distal clevis portion 125 c, as viewed from a side view when jaw members 210, 220 are disposed in the fully closed position.

A ratio of the length “L1” extending from the midpoint of pivot member 130 to the distal end of distal tip of jaw members 210, 220 (see FIGS. 1 and 17H) to the distance from the midpoint of pivot member 130 to the distal end of the lockbox configuration, “D2,” has also been found to facilitating tissue treatment, tissue division, and blunt tissue dissection. This ratio, L1/D2, in embodiments, is from about 1.80 to about 2.40; in other embodiments, from about 1.90 to about 2.30; in still other embodiments, from about 2.00 to about 2.20; and, in yet other embodiments, about 2.09.

Referring generally to FIGS. 28-30, it has further been found that, additionally or alternatively, that jaw stiffness is important. Jaw stiffness provides structural support but also defines the flexibility of the jaws, which flexion forms part of the overall spring system of forceps 10 (FIG. 1) to provide a suitable jaw force for treating, e.g., sealing, tissue grasped between jaw members 210, 220. The stiffness of jaw members 210, 220 is thus the ability of jaw members 210, 220 to resist deflection away from one another, e.g., in response to force(s) applied substantially normal to the tissue-contacting surfaces thereof.

Stiffness, more specifically, is measured as displacement of distal tip portion 280 in response to a force applied at distal tip portion 280 in a direction substantially normal to the tissue-contacting surface of the jaw member 210, 220. The displacement may be measured relative to the center of pivot 130 or, in other embodiments, may be measured relative to the position where jaw member 210 emerges from distal clevis portion 125 c, as viewed from a side view of jaw members 210, 220.

Overall, the stiffness of either or both jaw members 210, 220, from either measurement point, may be from about 80 lb/in to about 300 lb/in; in embodiments, from about 90 lb/in to about 250 lb/in; and, in embodiments, from about 100 lb/in to about 200 lb/in. The jaw members 210, 220 may have similar or different stiffnesses. The stiffness of jaw member 210 as measured relative to the center of pivot 130 may be, in embodiments, from about 80 lb/in to about 160 lb/in; in other embodiments, from about 100 lb/in to about 140 lb/in; and in still other embodiments, from about 110 lb/in to about 130 lb/in. The stiffness of jaw member 210, as measured relative to the position where jaw member 210 emerges from distal clevis portion 125 c may be, in embodiments, from about 100 lb/in to about 180 lb/in; in other embodiments, from about 120 lb/in to about 160 lb/in; and, in yet other embodiments, from about 130 lb/in to about 150 lb/in.

The stiffness of jaw member 220 as measured relative to the center of pivot 130 may be, in embodiments, from about 110 lb/in to about 190 lb/in; in other embodiments, from about 130 lb/in to about 170 lb/in; and in still other embodiments, from about 140 lb/in to about 160 lb/in. The stiffness of jaw member 220, as measured relative to the position where jaw member 210 emerges from distal clevis portion 125 c may be, in embodiments, from about 145 lb/in to about 225 lb/in; in other embodiments, from about 165 lb/in to about 205 lb/in; and, in yet other embodiments, from about 175 lb/in to about 195 lb/in.

The various embodiments disclosed herein may also be configured to work with robotic surgical systems and what is commonly referred to as “Telesurgery.” Such systems employ various robotic elements to assist the surgeon and allow remote operation (or partial remote operation) of surgical instrumentation. Various robotic arms, gears, cams, pulleys, electric and mechanical motors, etc. may be employed for this purpose and may be designed with a robotic surgical system to assist the surgeon during the course of an operation or treatment. Such robotic systems may include remotely steerable systems, automatically flexible surgical systems, remotely flexible surgical systems, remotely articulating surgical systems, wireless surgical systems, modular or selectively configurable remotely operated surgical systems, etc.

The robotic surgical systems may be employed with one or more consoles that are next to the operating theater or located in a remote location. In this instance, one team of surgeons or nurses may prep the patient for surgery and configure the robotic surgical system with one or more of the instruments disclosed herein while another surgeon (or group of surgeons) remotely control the instruments via the robotic surgical system. As can be appreciated, a highly skilled surgeon may perform multiple operations in multiple locations without leaving his/her remote console which can be both economically advantageous and a benefit to the patient or a series of patients.

The robotic arms of the surgical system are typically coupled to a pair of master handles by a controller. The handles can be moved by the surgeon to produce a corresponding movement of the working ends of any type of surgical instrument (e.g., end effectors, graspers, knifes, scissors, etc.) which may complement the use of one or more of the embodiments described herein. The movement of the master handles may be scaled so that the working ends have a corresponding movement that is different, smaller or larger, than the movement performed by the operating hands of the surgeon. The scale factor or gearing ratio may be adjustable so that the operator can control the resolution of the working ends of the surgical instrument(s).

The master handles may include various sensors to provide feedback to the surgeon relating to various tissue parameters or conditions, e.g., tissue resistance due to manipulation, cutting or otherwise treating, pressure by the instrument onto the tissue, tissue temperature, tissue impedance, etc. As can be appreciated, such sensors provide the surgeon with enhanced tactile feedback simulating actual operating conditions. The master handles may also include a variety of different actuators for delicate tissue manipulation or treatment further enhancing the surgeon's ability to mimic actual operating conditions.

From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

What is claimed is:
 1. An electrosurgical forceps, comprising: first and second shaft members; first and second jaw members extending distally from the respective first and second shaft members, each of the first and second jaw members including an inwardly-facing side and an outwardly-facing side, each of the first and second jaw members including a half-ellipse distal tip portion having a curved distal perimeter defined at an outer periphery of the first or second jaw member and a linear proximal perimeter serving as a dividing line between the half-ellipse distal tip portion and the rest of the first or second jaw member; and a pivot coupling the first and second shaft members with one another such that the first and second shaft members are movable relative to one another between a spaced-apart position and an approximated position to move the first and second jaw members relative to one another between an open position and a closed position, wherein a ratio of a height defined between the outwardly-facing sides of the first and second jaw members at the half-ellipse distal tip portions thereof in the closed position to a length of the half-ellipse distal tip portion of each of the first and second jaw members is in a range of from about 2.25 to about 2.55, wherein the length is a radius of the half-ellipse distal tip portion of each of the first and second jaw members, and wherein the height is measured through a diameter of the half-ellipse distal tip portion of each of the first and second jaw members that is aligned with the linear proximal perimeter of the half-ellipse distal tip portions.
 2. The electrosurgical forceps according to claim 1, wherein the ratio is in a range of from about 2.30 to about 2.50.
 3. The electrosurgical forceps according to claim 1, wherein the ratio is in a range of from about 2.35 to about 2.45.
 4. The electrosurgical forceps according to claim 1, wherein the ratio is about 2.40.
 5. The electrosurgical forceps according to claim 1, wherein each of the first and second jaw members is curved along a portion of a length thereof.
 6. The electrosurgical forceps according to claim 1, wherein, in the closed position, the half-ellipse distal tip portions of the first and second jaw members define a gap distance therebetween of equal to or less than about 0.025 inches. 